Astronomers use a wide variety of tools
in order to observe and collect data. The
electromagnetic spectrum provides the template to
design and implement instrumentation for study, and
lessons learned by other specialties have also been
brought to bare on a variety of topics.

Astronomy is the study of everything - as coined by Carl Sagan, this includes
understanding certain phenomenon here on Earth. Atmospheric studies and
geography are examples. The list of specialties
sometimes called on by astronomers include:
meteorology, paleontology, biology, geography,
seismology,
physics, chemistry,
quantum physics and computer
science.

Paleontology and the
study of ancient rock structures here on Earth can
help us understand the newly discovered nuances of
rock formations and ancient riverbeds on
Mars.

Biology combined with astronomy is a relatively new
field called
Astrobiology. The newly discovered extremophiles in our own deep oceans as well as the
evidence of previous liquid water on
Mars has
allowed this subspecialty to grow. Combine this with
the oceans under the icy sheet of
Europa and the
primordial atmosphere on
Titan, and we have an exciting future.

Geography, the study of land
mass formation and cratering, allow us to understand
meteorite impacts on the other
planets and moons so
we can better understand the evolution of the crust
of the terrestrial
planets. By studying
volcanism
and plate tectonics, we gain knowledge of how
volcanoes and land mass motions occur elsewhere.

Seismology is also a fairly new subspecialty in
astronomy. Our
Sun and other
stars have demonstrated
to seismic vibrations, and we are slowly beginning
to understand what this means. Studying
earthquake
phenomenon here on Earth will help us understand
this phenomenon elsewhere.

Physics is used heavily
in astronomy. This allows us to understand the
nature of
light and gravity as well as
orbital
motion. Modified Newtonian physics have given rise to
Einstein's Relativity as
to the study of particle and wave nature of
light.

Chemistry allows us to determine to chemical
composition of space dust,
stars,
planets, and so
forth. Variations of elements, called isotopes, can
also help us create timelines of chemical evolutions
of stars and
planets.

As you can
see, there is a large pool of knowledge and
experience that astronomers can draw from. The study
of these specialties greatly enhance our knowledge
of astronomical phenomenon and those results in turn
enhance the subjects from which we draw.